Determine whether the initial use of two non-nucleoside reverse transcriptase inhibitors (NRTIs) + nelfinavir (NFV) followed by a different two NRTIs + efavirenz (EFV) is superior to the initial use of two NRTIs + EFV followed by a different two NRTIs + NFV. Determine whether initial use of two NRTIs + NFV + EFV is superior to either of the two consecutive 3 drug regimens. Determine whether 3TC/ZDV followed by ddI + D4T is superior to ddI + d4T followed by 3TC/ZDV when these NRTI combinations are taken with NFV or EFV.